Electric-arc lamp.



PATENTEDJULY 5, 1904.

A. BLONDEL.

ELECTRIC ARC LAMP.

APPLIOATION FILED 10mm, 190s.

NO MODEL.

.largely mineralized UNITED STATES Patented July 5, 1904.

PATENT OEEicE.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 764,105, dated July 5, 1904.

Application filed December 22, 1903. Serial No. 186,163.

T0 (1J/Z whmn it Wbcty concern:

Be it known that l, ANDR BLONDEL, a citi- Zen of the Republic of France, residing at Paris, in the Republic of France, have invented a new and useful Improvement in Arc- Lamps, which improvement is fully set forth in the following specification.

The specification of the United States Patent No. 739,977, dated September 29, 1903, describes a combination of are-lamp in which a scoria-producing carbon may be used by placing it beneath another less mineralized carbon, the latter surrounded by a dome or reiiector provided with a refractory base which prevents the vapors passing away, thus allowing the fumes to be maintained in the arc. These are brought to incandescence and prevented from condensing upon the upper point, which parts with its heat to a very limited extent. Thespecification also claims the novel application of the dome to all mineralized arcs in view of the special results obtained.

This invention has for its object animprovement by which the'amount of mineral substances in the upper carbon (whatever may be its polarity) may be increased, if desired. A special disadvantage presents itself in this case consequent on the formation of scoria around the point of the upper carbon so soon as its mineralization is greater than seven to eight per cent. The scoria forms, as shown in Fig. l, a swell around the point of the carbon, where it collects instead of falling in drops. This swell thereupon prevents the upper carbon from moving freely upward through the hole in the reflector when striking the arc and when drawing it out by the top when the carbons are changed. Moreover, the scoria may ultimately attack and fuse the refractory material forming the reflector, (which may be a dome, crucible, or disk,) which surrounds the carbon near to its point. Lastly, it falls in drops upon the point of the lower carbon.

The improvement forming the object of the present invention consists in surrounding the upper carbon with a protecting-envelop a of carbon, which not only enormously reduces the formation and fall of scoria, but also forms (in order to allow the carbon to be easily withlNe model.)

l drawn) a space between the scoria-forming portion of the carbon and the walls of the hole in the reiiector. The said hole may, moreover, be advantageously cut away for a certain distance toward the bottom, forming a conical, spherical, cylindrical, or other enlargement, as shown in Figs. 3, 5, and 6, in order to more surely prevent scoria touching the walls. Figs. 2, 3, e, 5, and 6 show examples of this envelop in several different forms of reflector. The carbon envelop is consumed little by little and should consequently be fed forward bit by bit. This forward movement may take place in one or other of the following` ways:

First. As shown in Fig. 6, the top of the envelop (which is shorter than the upper carbon) is fixed in an independent annular carbon-carrier, supported by a rod, chain, or cord analogous to that which supports the carbon-carrier of the central carbon and receives through the lamp mechanism a similar but smaller movement than that of the carbon. The said movement is empirically regulated in such a manner that the advance is proportional to the consumption. lt is not necessary to enter here into the details of the mechanism, which is capable of numerous forms 'within the reach of any mechanic.

Second. As shown in Figs. Q, 3, et, and 5, the envelop of the carbon,which it surrounds, is so iixed that the envelop advances with the carbon without separating from it. The thickness of said envelop is so chosen that it is consumed as. fast as the inner carbon and leaves the carbon always flush with it or projecting a little out from the said envelop. The envelop may even be manufactured together with the carbon and have given to it conducting properties advantageous to the passage of the current and the decrease of consumption, according to the arrangements indicated in Blondels patent, No. Tlf-i277, of November Q5, 1902. These carbons then have the advantages indicated in this patent and also the additional advantages of the combination set out above, which render the employment of the reflector more practical. The envelop may also be made fairly thick when the reflector is quite open, as when diskshaped, as shown in Fig. e, or when it is de- IOC bon is completely exposed sired that the end of the upper carbon should project still v more below the reflector, as shownv in Fig. 8, for in thesetwo cases the consumption of the envelop is increased, for the carto the free air.

Third. A last and slightly-different solution is for the envelop to form the base of the reflector surrounding the carbon, as shown in Fig. 7-that is to say, this portion of the refiector may be made of pure carbon, which is little combustible if of agraphite-like nature or mixed with small quantities of mineral substances-for example, magnesia or noninfiammable substances which form white cinders at the lower surface. Such a piece of carbon consumes slowly and may be easily renewed when changing the carbons. As it is very refractory and -not attacked by scoria, it may be placed around the point ofthe carbon quite near to the arc.

These different arrangements of carbon envelops placed betweenthe upper carbon and the Arefiector find application in several cases in which a mineralized arc is used, viiz:

First. In acontinuous-current arc, the positive .being aboveand the negative below, the arc beingformed between any carbon, whether ordinary or mineralized, whether homogeneous or provided with .a .core and with or without an envelop. In thiscombination the positive is `kept hotterthan .when the arc is inverted; but there may bean excess of scoria if the mineralized portionofthepositive carbon be too highly mineralized. A mineralization of twenty-five per cent., for example, would bellsuiiicient.

Second. IIn a continuous-current arc havingthe fpositive placed underneath when it is wished to more highly mineralize the ,negative, the positive being, if desired, also mineralized.

Third. In analternating-current are having both carbons mineralized.

In all these applications the refiecting dome, crucible, or disk still possesses the useful properties already mentioned.

Fourth. Lastly,in continuous-currentlamps of any type having' any numberof carbons mineralized (or in which one at least is mineralized) placed side by side with points downward, Fig. 8.

In thiscase, again, a notable improvement these lamps is effected, for not only does the covering ofl carbon reduce the fall of scoria and protect the holes in the refiector, as above stated, but it also permits the are to be formed with safety by moving the two carbons together. In effect, even if drops are formed the lower portions of the envelop a remain clean, and excellent contact may be formed between them when the carbons are lowered until they touch each other.

What I claim is- 1.- In an arc-lamp, the combination, with a reflector having an opening, of' a mineralized movable electrode projecting through said opening, and a protective envelop extending into said opening' and surrounding the min- I eralized electrode.

2. In an arc-lamp, the combination, with a refiector having an opening, of a mineralized movable electrode projecting through said opening, and a protective carbon-envelop extending into said opening andv surrounding' the mineralized electrode.

3. In an arc-lamp, the combination, with a carbon refiectorhaving an opening, of amineralized movable electrodeprojecting through said opening, and a protective carbon-envelop extending into `said opening and surrounding the mineralized electrode.

4. In an arc-lamp, the combination, with a reflector having an opening, of a mineralizedv movable electrode Aprojecting through said opening, and aprotective envelopextending into said opening and surroundingthe mineralized electrode, said envelop being movable with relation to saidelectrode.

5. In an arc-lamp, the combination, with a refiector having an 4electrode-opening, of a scoria-producing electrode movable through said opening and a protective envelop surrounding said electrode and extending' into said opening in the refiector.

In an arc-lamp, the combination, with a refiector having an electrode-opening, said reflector beingcutaway adjacent said opening, substantially as described, of a scoria-producing electrode movable through said opening, and a protective envelop surrounding said electrode and extending through said opening in the reflector.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

ANDR BLONDEL. litnesses:

HENRY ZEUTo'r, PAUL F. PQUET.

IOO 

